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POError sending JSON object to asp.net WebMethod, using jQuery
 

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  1. POError sending JSON object to asp.net WebMethod, using jQuery
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    <p>I get an error of "Cannot convert object of type System.String' to type 'System.Collections.Generic.List'1[...+ContactHolder]'"</p> <p>This is my C# code:</p> <pre><code>public class ContactHolder{ public String Name { get; set; } public String Address { get; set; } } [WebMethod] public static string AddContact(Object items){ List&lt;ContactHolder&gt; contacts = new JavaScriptSerializer().ConvertToType&lt;List&lt;ContactHolder&gt;&gt;(items); return String.Format("You added {0} contacts!", contacts.ToString()); } </code></pre> <p>This is my Javascript code (note I have included jquery-1.4.1.js and json2.js in my project)</p> <pre><code>function Test() { var arr = new Array(); var contact = new Object(); contact.Name = "Ben"; contact.Address = "Ohio"; var contact2 = new Object(); contact.Name = "Jon"; contact.Address = "Illinois"; arr[1] = contact; arr[2] = contact2; var DTO = JSON.stringify(arr); PageMethods.AddContact(DTO, OnMyMethodComplete);} function OnMyMethodComplete(result, userContext, methodName) {alert(result);} </code></pre> <p>When I pass DTO into myPageMethod it looks like this: "[{"Name":"Ben","Address":"Ohio"},{"Name":"Jon","Address":"Illinois"}]"</p> <p>When it appears in my WebMethod as items it looks like this: "[{\"Name\":\"Ben\",\"Address\":\"Ohio\"},{\"Name\":\"Jon\",\"Address\":\"Illinois\"}]"</p> <p>The code errors on the call to JavaScriptSerializer().ConvertToType, the message is {"Cannot convert object of type System.String' to type 'System.Collections.Generic.List'1[...+ContactHolder]'"}</p> <p>What do I need to do to make this work? </p>
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    1. USBen Hoffman
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    1. COCan you post the implementation of `PageMethods.AddContact`? I think it would be more easier to help you if we know exactly what is going on behind the scenes.
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      1. USHerberth Amaral
    2. COWhy do you not declare the WebMethod parameter as ContactHolder[] ? Seems as if ASP.Net sees a scalar parameter (Object), and converts the JSON string into a .Net string.
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    3. CO@Herberth - I do include the code for AddContact. It is in the C# code section.
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      1. USBen Hoffman
 

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